The present invention provides a hand tool for imparting compressive forces upon an object, and more particularly, a hand tool having opposing pivotal members for receiving an object and an extension of one of the pivotal members permitting striking of the extension to effect sudden and rapid compression of the object. The hand tool and method of use are applicable to the cracking of nuts, lobster shells, crab shells, or other objects requiring the application of force to effect fracturing thereof, and also the installation of items requiring compression, such as grommets.
Various tools for cracking nut shells and other shells are known. Generally, such cracking tools have pivoting members providing for the placement of an object to be cracked between the pivoting members. The user then uses muscles effecting closure of the user's hand to apply a compressive force to the pivoting members to compress and crack the object. This type of cracking tool requires that the user have sufficient strength to apply a force capable of cracking the object. The length of the pivoting members may be extended to provide a greater mechanical advantage than a shorter cracking tool of similar design. As a consequence of increasing the pivoting member length, the force required to crack an object is reduced at the expense of increasing the travel of the pivoting members. Cracking tools having an adequate mechanical advantage to permit use by individuals having limited strength, such as children and the elderly, are longer than would be preferred and unwieldy. Furthermore, the increased travel of the pivoting members is particularly disadvantageous for children because the hand span of a child may very well be less than the travel range of the pivoting member requiring the child to use two hands to operate the device.
A second type of known cracking tool employs a screw mechanism. The cracking tool has a cavity for receiving an object to be cracked and a threaded aperture through which a screw member is advanced into the cavity to apply force to crack the object. The pitch of the threads determines the mechanical advantage achieved by the cracking tool dictating a torque necessary for cracking the object. Cracking tools of the screw type configuration having a coarse pitch often require more torque than a child, or physically challenged person can apply. Screw type cracking tools having a fine pitch allow operation with less torque but require a greater number of revolutions to effect cracking than a cracking tool having a coarse pitch. The increased number of revolutions required for operation can result in fatigue of the user's wrist.
A third type of known tool is of a mallet type. The mallet type cracking tool generally has a mallet and a holder for the object to be compressed or cracked. The user places the object to be cracked in the holder and strikes the object with the mallet. Such operation presents the possibility of pieces of the cracked object being scattered by the impact of the mallet. Furthermore, the mallet and holder are independent of each other and are thus prone to be separated and misplaced.
Another type of operation requiring the application of compressive forces is the installation of grommets. Grommets are generally comprised of a ring piece and a ring and post piece. The ring piece is placed on a first side of a material having a hole therein and the ring and post piece is inserted through the hole in the material and the ring piece. Once in place, the ring and post piece is place upon an anvil piece and a swaging tool is placed over the post protruding the ring piece. The swaging tool is struck with a mallet and deforms the post over the ring piece effecting installation of the grommet. While the process is effective, several distinct tool pieces are required, the anvil piece, the swaging tool, and the mallet. The distinct pieces are thus prone to being misplaced and separated.